Embattled New York City mayoral candidate Anthony Weiner said Sunday that he would not pull out of the race, even as he confirmed that his campaign manager had quit amid a mounting scandal, and that his chief opponent called him unfit to run the city, USA Today reports.

Weiner said that campaign manager Danny Kedem resigned after revelations came out last week that Weiner continued to send salacious messages online to women, even after resigning from Congress in 2011.

"We knew this would be a tough campaign," Weiner said while campaigning in Brooklyn. "We have an amazing staff, but this isn't about the people working on the campaign. It's about the people we're campaigning for."

The tumult in Weiner's staff was first reported by The New York Times. Hours later, City Council Speaker Christine Quinn repeated criticism on NBC's Meet the Press that Weiner has displayed "a pattern of reckless behavior, an inability to tell the truth and a real lack of maturity."

Quinn, who has a 9-point lead over Weiner, went beyond those comments when pressed if Weiner had disqualified himself by admitting he continued to send lewd messages after such behavior forced him to quit the U.S. House. As she noted her accomplishments on the City Council, Quinn pointed out that Weiner only managed to get one bill passed during his 12 years in Congress.